1. Field of the Invention
This invention relates to ice release agents for inhibiting the bonding of ice precipitates to a substrate, and in particular, to a non-toxic ice release composition which is stable and insoluble in water.
2. Description of the Prior Art
The bonding or adhesion of ice precipitates to unprotected vehicles, equipment and exposed structures is a common problem inasmuch as the ice or frost accumulation limits the utility of the equipment and shortens its useful life. Some equipment or vehicles cannot be garaged and are exposed to ice formation for long periods of time. A common occurence of ice precipitation is ice formation on automobile windshields and door panels. A considerable amount of time and effort must be expended to remove the ice so that the door can be opened and the automobile operated safely with good visibility through the windshield. Ice formation is also a problem in other areas where equipment is left unprotected or otherwise exposed to the elements, for example outdoor machinery such as electrical motors, compressors and the like, earth moving machinery, building structures, sidewalks and driveways. The removal of the accumulated ice precipitates from such equipment and structures in a serious and continuing problem which involves considerable time and expenditure.
Among the solutions which have been attempted to solve the ice accumulation problem are methods which remove existing accumulations of ice by melting the ice, methods that utilize a permanent ice release coating on the surface of the structure to be protected, and methods that involve the use of a temporary ice release coating on the surface of the structure.
The use of temporary release agents, while being both practical and economical, has been limited because the film thickness of the ice release agent has been too thin to prevent the bonding of ice precipitates on non-horizontal surfaces such as the windshield of an automobile. Moreover, the duration of protection for such ice release agents has been limited because of the relatively rapid evaporation rate of the formulation. The effectiveness of water-soluble ice release compositions has also been limited by the tendency to be rapidly diluted when contacted by the ice precipitates.
Conventional ice release compositions have been characterized by relatively low viscosity which causes them to drain away from non-horizontal surfaces thereby leaving an insufficient amount of the composition to provide an effective release layer. Other release compositions are toxic and thus may be used only under controlled conditions.